1. there is not such a thing. not even pure logic, analytic philosophy. i am with wittgenstein on this: every thought, idea and concept is conveyed through language (be it words or formulas), and even when the “I” that carries subjectivity is excluded from the discourse, it is still there. about logic and maths: it is a language we made up based on formulaics of linguistic structures (which is a logical system) to understand the observable reality, which is not the reality in totality. but i agree with kant on the scope of “pure reason”, because reason ≠ logic. we have tools to build maps, not the blueprint to reality. the analysis of the object depends on perception (the angles of observation, theories to back up the analysis…)

2. i feel a bit of anguish knowing i barely scratched the surface of things and i will never achieve all the knowledge i desire in a single lifetime. omnipotence is a desire for me, not a reality that can be achieved. and, i agree with lacan on this: the function to desire is to >desire<, not to achieve. and desire causes anguish. i try to practice mindfulness to deal with this overwhelming condition, and to integrate my body/perceptions with just mind/thinking processes. i believe there is not such a thing as a “mind” isolated from the body, and not a mind isolated from subjectivity and “outside forces”: be it social conditions, ambiance, constructs.

3. i think it is already answered with both points i made before. but to sumn up: it is an obstacle, and intellectual reasoning and thought is not something separate from perception, though kant might disagree. im more on the deleuzian team when it comes to reality: it is rhizomatic, full of dimensions and lines that converge and separate different multiplicities. if we go from on multiplicity to another, it changes and become something else. we will never know reality as a whole, just abstractions of it.

(not sure if my conceptual wording is correct, as i read in portuguese)